Radon is a radioactive gas which emits alpha particles - Leaving Cert Physics - Question 10 - 2011

The other two types of radiation emitted by radioactive sources are beta (β) radiation and gamma (γ) radiation.

To distinguish between alpha, beta, and gamma radiation, the following experiment can be conducted:

Apparatus:

• Radioactive source in a lead container
• Electric/magnetic field setup
• Photographic plate

Procedure:

1. Place the radioactive source in an electric or magnetic field.
2. Observe the deflection of the radiation in the field using the photographic plate.

Observation:
Different types of radiation will deflect differently on the photographic plate:

• Alpha particles (α) will deflect towards the negative plate due to their positive charge.
• Beta particles (β) will deflect towards the positive plate since they are negatively charged.
• Gamma rays (γ) will not be deflected, as they have no charge.

This marks the method to identify different radiations based on their behaviors in electric and magnetic fields.

Considering alpha radiation, three properties are:

1. Nature: Alpha particles consist of helium nuclei (

   He nucleus).

2. Charge: They carry a positive charge (+2).

3. Range: Alpha particles have a limited range in air, typically only a few centimeters, and are stopped by a sheet of paper.

Isotopes are variants of the same chemical element that have the same number of protons but different numbers of neutrons. This results in different mass numbers for the isotopes of an element.

It is important to prevent radon gas from entering your home primarily because radon is a radioactive gas that can cause lung cancer upon long-term exposure. By sealing gaps and ensuring proper ventilation, the health risks associated with radon exposure can be minimized.

Radon has a half-life of 4 days. To find out when one-eighth of the radon gas would remain, we need to calculate how many half-lives that represents:

Since one-eighth is $\frac{1}{8}$, and each half-life reduces the remaining amount by half:

1. After 1 half-life: $\frac{1}{2}$
2. After 2 half-lives: $\frac{1}{4}$
3. After 3 half-lives: $\frac{1}{8}$

Therefore, it takes 3 half-lives to reduce the radon gas to one-eighth, which is $3 \times 4 = 12$ days.

Two uses of radioisotopes include:

1. Medical Imaging: Radioisotopes are used in medical imaging techniques, such as PET scans, to visualize the internal functioning of organs.
2. Cancer Treatment: Radioisotopes are employed in radiation therapy to target and destroy cancerous cells.